Closed compressor

ABSTRACT

Disclosed is an enclosed type compressor ( 1 ) in which a scroll type compression mechanism ( 2 ) and an electric motor ( 3 ) are attached firmly to a casing ( 6 ), with the scroll type compression mechanism ( 2 ) and the electric motor ( 3 ) in contact with an inner face of the casing ( 6 ). Formed in a plane orthogonal to the longitudinal direction of the casing ( 6 ) are a contact part ( 20, 21 ) of the casing ( 6 ) which makes contact with the scroll type compression mechanism ( 2 ) (the electric motor ( 3 )) and a non-contact part ( 30, 31 ) of the casing ( 6 ) which does not make contact with the scroll type compression mechanism ( 2 ) (the electric motor ( 3 )). The non-contact part ( 30 ) with respect to the scroll type compression mechanism ( 2 ) has a peripheral length different from that of the non-contact part ( 31 ) with respect to the electric motor ( 3 ).

TECHNICAL FIELD

The present invention relates to enclosed type compressors for use inairconditioners or the like. The present invention pertains totechniques for achieving the reduction of vibration and noise fromconstituent components of such an enclosed type compressor (e. g,. acompression mechanism, an electric motor, a bearing et cetera).

BACKGROUND ART

As a compressor for use in airconditioners and refrigerating machines,enclosed type compressors have been known in the art. In such anenclosed type compressor, a compression mechanism, an electric motor,and other constituent components are all housed in a single casing forthe purpose of space saving and leakage prevention.

Additionally, in an enclosed type compressor a compression mechanism anda stator of an electric motor are attached firmly to a casing.Consequently, vibrations from the compression mechanism and electricmotor travel to the casing, thereby causing the problem that noise isemitted from a wide region of the casing surface.

Such a problem has conventionally been dealt with by improvement incasing rigidity. More specifically, measures of increasing the thicknessof a casing itself and of extending the area of contact, for example,between the casing and the compression mechanism have been taken.

PROBLEMS THAT INVENTION INTENDS TO SOLVE

However, if the thickness of a casing is increased, this results in theincrease in the total weight of a compressor, therefore causing anotherproblem that the costs of materials increase. Accordingly, the costs ofproduction increase.

In addition, enclosed type compressors typically employ a constructionin which fluid prior to and posterior to compression flows in thecasing. Accordingly, if a means intended for increasing the area ofcontact between each constituent component and the casing is employed,this reduces the area of fluidflow in the casing. Consequently, smoothmovement of the fluid is prevented and the compressor's performancedrops.

Bearing in mind the above-mentioned problems, the present invention wasmade. Accordingly, an object of the present invention is to provide animproved compressor which is quiet and reliable and, in addition, whichis able to prevent the increase in compressor weight itself

DISCLOSURE OF INVENTION

The present invention provides a first problem-solving means which is anenclosed type compressor comprising a scroll type compression mechanism(2), an electric motor (3) for driving the compression mechanism (2),and a cylindrical casing (6) for housing the compression mechanism (2)and the electric motor (3).

The compression mechanism (2) and the electric motor (3) are attachedfirmly to the casing (6), with the compression mechanism (2) and theelectric motor (3) in contact with an inside face of the casing (6). Ina first plane orthogonal to the longitudinal direction of the casing(6), the casing (6) is in contact with the compression mechanism (2) ina first contact part (20) and is out of contact with the compressionmechanism (2) in a first non-contact part (30). In a second planeorthogonal to the longitudinal direction of the casing (6), the casing(6) is in contact with the electric motor (3) in a second contact part(21) and is out of contact with the electric motor (3) in a secondnon-contact part (31). Additionally, the first non-contact part (30) andthe second non-contact part (31) have different peripheral lengths.

The present invention provides a second problem-solving means which isan enclosed type compressor comprising a compression mechanism (2), anelectric motor (3) for driving the compression mechanism (2), and acasing (6) for housing the compression mechanism (2) and the electricmotor (3).

The compression mechanism (2) and the electric motor (3) are attachedfirmly to the casing (6), with the compression mechanism (2) and theelectric motor (3) in contact with an inside face of the casing (6). Ina first plane orthogonal to the longitudinal direction of the casing(6), the casing (6) is in contact with the compression mechanism (2) ina first contact part (20) and is out of contact with the compressionmechanism (2) in a first non-contact part (30). In a second planeorthogonal to the longitudinal direction of the casing (6), the casing(6) is in contact with the electric motor (3) in a second contact part(21) and is out of contact with the electric motor (3) in a secondnon-contact part (31). Additionally, the first non-contact part (30) andthe second non-contact part (31) have different peripheral lengths.

The present invention provides a third problem-solving means which is anenclosed type compressor (1) comprising a scroll type compressionmechanism (2), an electric motor (3) for driving the compressionmechanism (2), a bearing (5) for supporting one end of a drive shaft (4)connecting the compression mechanism (2) and the electric motor (3), anda casing (6) for housing the compression mechanism (2), the electricmotor (3), and the bearing (5).

The compression mechanism (2), the electric motor (3), and the bearing(5) are attached firmly to the casing (6), with the compressionmechanism (2), the electric motor (3), and the bearing (5) in contactwith an inside face of the casing (6). In a first plane orthogonal tothe longitudinal direction of the casing (6), the casing (6) is incontact with the compression mechanism (2) in a first contact part (20)and is out of contact with the compression mechanism (2) in a firstnon-contact part (30). In a second plane orthogonal to the longitudinaldirection of the casing (6), the casing (6) is in contact with theelectric motor (3) in a second contact part (21) and is out of contactwith the electric motor (3) in a second non-contact part (31). In athird plane orthogonal to the longitudinal direction of the casing (6),the casing (6) is in contact with the bearing (5) in a third contactpart (22) and is out of contact with the bearing (5) in a thirdnon-contact part (32). Additionally, the first non-contact part (30),the second non-contact part (31), and the third non-contact part (32)have different peripheral lengths, respectively.

The present invention provides a fourth problem-solving means which isan enclosed type compressor according to any one of the first to thirdproblem-solving means, in which a plurality of the first contact parts(20) and a plurality of the first non-contact parts (30) with respect tothe compression mechanism (2) are formed in the casing (6).Additionally, at least one of the plurality of the first non-contactparts (30) with respect to the compression mechanism (2) has aperipheral length different from that of the other first non-contactparts (30).

The present invention provides a fifth problem-solving means which is anenclosed type compressor according to any one of the first to thirdproblem-solving means, in which a plurality of the second contact parts(21) and a plurality of the second non-contact part (31) with respect tothe electric motor (3) are formed in the casing (6). Additionally, atleast one of the plurality of the second non-contact parts (31) withrespect to the electric motor (3) has a peripheral length different fromthat of the other second non-contact parts (31).

The present invention provides a sixth problem-solving means which is anenclosed type compressor according to the third problem-solving means,in which a plurality of the third contact parts (22) and a plurality ofthe third non-contact parts (32) with respect to the bearing (5) areformed in the casing (6). Additionally, at least one of the plurality ofthe third non-contact parts (32) with respect to the bearing (5) has aperipheral length different from that of the other third non-contactparts (32).

The present invention provides a seventh problem-solving means which isan enclosed type compressor according to either the firstproblem-solving means or the second problem-solving means, in which thenumber of the first contact parts (20) with respect to the compressionmechanism (2) differs from the number of the second contact parts (21)with respect to the electric motor (3).

The present invention provides an eighth problem-solving means which isan enclosed type compressor according to the third problem-solvingmeans, in which the number of the first contact parts (20) with respectto the compression mechanism (2), the number of the second contact parts(21) with respect to the electric motor (3), and the number of the thirdcontact parts (22) with respect to the bearing (5) differ from oneanother.

The present invention provides a ninth problem-solving means which is anenclosed type compressor according to either the first problem-solvingmeans or the second problem-solving means, in which the number of thefirst non-contact parts (30) with respect to the compression mechanism(2) is neither a multiple nor a divisor of the number of the secondnon-contact parts (31) with respect to the electric motor (3).

The present invention provides a tenth problem-solving means which is anenclosed type compressor according to the third problem-solving means,in which the number of the first non-contact parts (30) with respect tothe compression mechanism (2) is neither a multiple nor a divisor of thenumber of the second non-contact parts (31) with respect to the electricmotor (3). Additionally, the number of the second non-contact parts (31)with respect to the electric motor (3) is neither a multiple nor adivisor of the number of the third non-contact parts (32) with respectto the bearing (5), and the number of the third non-contact parts (32)with respect to the bearing (5) is neither a multiple nor a divisor ofthe number of the first non-contact parts (30) with respect to thecompression mechanism (2).

Working

In the first to third problem-solving means, the electric motor (3)drives the compression mechanism (2) to rotate. The compressionmechanism (2) sucks in low-pressure fluid and compresses it to a highpressure level. Thereafter, the compression mechanism (2) discharges thehigh-pressure fluid. During that period, the compression mechanism (2)and the electric motor (3) produce vibrations. The compression mechanism(2) and the electric motor (3) are in contact with the casing (6).Accordingly, the vibrations produced in the compression mechanism (2)and the electric motor (3) propagate to the contact parts of the casing(6), thereby causing the non-contact parts of the casing (6) to vibrate.

In the first problem-solving means, the peripheral length of the firstnon-contact part (30) with respect to the scroll type compressionmechanism (2) differs from the peripheral length of the secondnon-contact part (31) with respect to the electric motor (3). Further,in the second problem-solving means the peripheral length of the firstnon-contact part (30) with respect to the compression mechanism (2)differs from the peripheral length of the second non-contact part (31)with respect to the electric motor (3). As a result of such arrangement,the frequency of vibration occurring when excitation force is applied tothe first non-contact part (30) from the compression mechanism (2)differs from the frequency of vibration occurring when excitation forceis applied to the second non-contact part (31) from the electric motor(3).

In the third problem-solving means, the peripheral length of the firstnon-contact part (30) with respect to the scroll type compressionmechanism (2), the peripheral length of the second non-contact part (31)with respect to the electric motor (3), and the peripheral length of thethird non-contact part (32) with respect to the bearing (5) differ fromone another. As a result of such arrangement, the frequency of vibrationoccurring when excitation force is applied to the first non-contact part(30) from the compression mechanism (2), the frequency of vibrationoccurring when excitation force is applied to the second non-contactpart (31) from the electric motor (3), and the frequency of vibrationoccurring when excitation force is applied to the third non-contact part(32) from the bearing (5) differ from one another.

In the fourth problem-solving means, at least one of the plural firstnon-contact parts (30) with respect to the compression mechanism (2) hasa peripheral length different from that of the other first non-contactparts (30). Accordingly, with respect to the compression mechanism (2),there is a difference in vibration frequency between the one firstnon-contact part (30) and the other first non-contact parts (30).

In the fifth problem-solving means, at least one of the plural secondnon-contact parts (31) with respect to the electric motor (3) has aperipheral length different from that of the other second non-contactparts (31). Accordingly, with respect to the electric motor (3), thereis a difference in vibration frequency between the one secondnon-contact part (31) and the other second non-contact parts (31).

In the sixth problem-solving means, at least one of the plural thirdnon-contact parts (32) with respect to the bearing (5) has a peripherallength different from that of the other third non-contact parts (32).Accordingly, with respect to the bearing (5), there is a difference invibration frequency between the one third non-contact part (32) and theother third non-contact parts (32).

In the seventh problem-solving means, the number of the first contactparts (20) with respect to the compression mechanism (2) is differentfrom the number of the second contact parts (21) with respect to theelectric motor (3). Accordingly, such a difference between the number ofthe first contact parts (20) and the number of the second contact parts(21) causes the number of the first non-contact parts (30) to differfrom the number of the second non-contact parts (31). As a result, thefrequency of vibration occurring in the first non-contact part (30)differs from the frequency of vibration occurring in the secondnon-contact part (31).

In the eighth problem-solving means, the number of the first contactparts (20) with respect to the compression mechanism (2), the number ofthe second contact parts (21) with respect to the electric motor (3),and the number of the third contact parts (22) with respect to thebearing (5) differ from one another. Accordingly, such differences amongthe number of the first contact parts (20), the number of the secondcontact parts (21), and the number of the third contact parts (22) causethe number of the first non-contact parts (30), the number of the secondnon-contact parts (31), and the number of the third non-contact parts(32) to differ from one another. As a result, the frequency of vibrationoccurring in the first non-contact part (30), the frequency of vibrationoccurring in the second non-contact part (31), and the frequency ofvibration occurring in the third non-contact part (32) differ from oneanother.

In the ninth problem-solving means, the number of the first contactparts (20) with respect to the compression mechanism (2) is neither amultiple nor a divisor of the number of the second contact parts (21),and vice versa. If the numbers of these contact parts (20, 21) are in amultiple or a divisor relationship with each other, for example if thenumber of the second contact part (21) is twice the number of the firstcontact parts (20), there is the possibility that the secondary mode ofvibration of the first non-contact part (30) and the primary mode ofvibration of the second non-contact part (31) resonate. In the presentproblem-solving means, however, it is arranged such that the number ofthe second contact parts (21) is neither a multiple nor a divisor of thenumber of the first contact part (20), thereby preventing the occurrenceof such resonance.

In the tenth problem-solving means, each of the number of the firstcontact parts (20) with respect to the compression mechanism (2), thenumber of the second contact parts (21) with respect to the electricmotor (3), and the number of the third contact parts (22) with respectto the bearing (5) is neither a multiple nor a divisor of the other.Accordingly, the multi-modes of vibrations occurring in the first tothird non-contact parts (30, 31, 32) will not resonate.

Effects of Invention

In the present invention, when vibrations occurring in the compressionmechanism (2) and other components propagate to the casing (6), thevibrations are cancelled or averaged because the non-contact parts (30,31, 32) differ from one another in vibration frequency. This,consequently, prevents sound of a particular frequency from beingemitted noisily. Consequently, the reduction of vibration and thereduction of noise are achieved as a whole in the enclosed typecompressor.

In the first problem-solving means, the peripheral length of the firstnon-contact part (30) with respect to the scroll type compressionmechanism (2) differs from the peripheral length of the secondnon-contact part (31) with respect to the electric motor (3). Therefore,the frequency of vibration occurring in the first non-contact part (30)differs from the frequency of vibration occurring in the secondnon-contact part (31). Accordingly, these vibrations of differentvibration frequencies are cancelled or averaged, thereby preventingsound of a particular frequency from being emitted noisily.Consequently, the reduction of vibration and the reduction of noise areachieved as a whole in the enclosed type compressor.

In the second problem-solving means, the peripheral length of the firstnon-contact part (30) with respect to the compression mechanism (2)differs from the peripheral length of the second non-contact part (31)with respect to the electric motor (3). Therefore, the frequency ofvibration occurring in the first non-contact part (30) differs from thefrequency of vibration occurring in the second non-contact part (31), asin the first problem-solving means. Accordingly, these vibrations ofdifferent vibration frequencies are cancelled or averaged, therebypreventing sound of a particular frequency from being emitted noisily.Consequently, the reduction of vibration and the reduction of noise areachieved as a whole in the enclosed type compressor.

In the third problem-solving means, the peripheral length of the firstnon-contact part (30) with respect to the scroll type compressionmechanism (2), the peripheral length of the second non-contact part (31)with respect to the electric motor (3), and the peripheral length of thethird non-contact part (32) with respect to the bearing (5) differ fromone another. Therefore, the frequency of vibration occurring in thefirst non-contact part (30), the frequency of vibration occurring in thesecond non-contact part (31), and the frequency of vibration occurringin the third non-contact part (32) differ from one another. Accordingly,these vibrations of different vibration frequencies are cancelled oraveraged, thereby preventing sound of a particular frequency from beingemitted noisily. Consequently, the reduction of vibration and thereduction of noise are achieved as a whole in the enclosed typecompressor.

In the fourth problem-solving means, at least one of the plural firstnon-contact parts (30) with respect to the compression mechanism (2) hasa peripheral length different from that of the other first non-contactparts (30). Accordingly, the frequency of vibration occurring in the onefirst non-contact part (30) differs from the frequency of vibrationoccurring in the other first non-contact parts (30) because of thedifference in peripheral length. Accordingly, these vibrations ofdifferent frequencies are cancelled or averaged, thereby preventingsound of a particular frequency from being emitted noisily.Consequently, the reduction of vibration and the reduction of noise areachieved as a whole in the enclosed type compressor.

In the fifth problem-solving means, at least one of the plural secondnon-contact parts (31) with respect to the electric motor (3) has aperipheral length different from that of the other second non-contactparts (31). Accordingly, the frequency of vibration occurring in the onesecond non-contact part (31) differs from the frequency of vibrationoccurring in the other second non-contact parts (31) because of thedifference in peripheral length. Accordingly, these vibrations ofdifferent vibration frequencies are cancelled or averaged, therebypreventing sound of a particular frequency from being emitted noisily.Consequently, the reduction of vibration and the reduction of noise areachieved as a whole in the enclosed type compressor.

In the sixth problem-solving means, at least one of the plural thirdnon-contact parts (32) with respect to the bearing (5) has a peripherallength different from that of the other third non-contact parts (32).Accordingly, the frequency of vibration occurring in the one thirdnon-contact part (32) differs from the frequency of vibration occurringin the other third non-contact parts (32) because of the difference inperipheral length. Accordingly, these vibrations of different vibrationfrequencies are cancelled or averaged, thereby preventing sound of aparticular frequency from being emitted noisily. Consequently, thereduction of vibration and the reduction of noise are achieved as awhole in the enclosed type compressor.

In the seventh problem-solving means, the number of the first contactparts (20) with respect to the compression mechanism (2) differs fromthe number of the second contact parts (21) with respect to the electricmotor (3). Therefore, the number of the first non-contact parts (30)differs from the number of the second non-contact parts (31), and theperipheral length of the first non-contact part (30) differs from theperipheral length of the second non-contact part (31). Accordingly, thefrequency of vibration occurring in the first non-contact part (30)differs from the frequency of vibration occurring in the secondnon-contact part (31). These vibrations of different vibrationfrequencies are cancelled or averaged, thereby preventing sound of aparticular frequency from being emitted noisily. Consequently, thereduction of vibration and the reduction of noise are achieved as awhole in the enclosed type compressor.

In the eighth problem-solving means, the number of the first contactparts (20) with respect to the compression mechanism (2), the number ofthe second contact parts (21) with respect to the electric motor (3),and the number of the third contact parts (22) with respect to thebearing (5) differ from one another. Therefore, the number of the firstnon-contact parts (30), the number of the second non-contact parts (31),and the number of the third non-contact parts (32) differ from oneanother and, in addition, the peripheral length of the first non-contactpart (30), the peripheral length of the second non-contact part (31),and the peripheral length of the third non-contact part (32) differ fromone another. Accordingly, the frequency of vibration occurring in thefirst non-contact part (30), the frequency of vibration occurring in thesecond non-contact part (31), and the frequency of vibration occurringin the third non-contact part (32) differ from one another. Accordingly,these vibrations of different vibration frequencies are cancelled oraveraged, thereby preventing sound of a particular frequency from beingemitted noisily. Consequently, the reduction of vibration and thereduction of noise are achieved as a whole in the enclosed typecompressor.

In the ninth problem-solving means, the multi-mode of vibrationoccurring in the first non-contact part (30) and the multi-mode ofvibration occurring in the second non-contact parts (31) do notresonate, thereby effectively canceling the vibrations.

In the tenth problem-solving means, the multi-mode of vibrationoccurring in the first non-contact parts (30), the multi-mode ofvibration occurring in the second non-contact parts (31), and themulti-mode of vibration occurring in the third non-contact part (32) donot resonate, thereby effectively canceling the vibrations.

Further, in accordance with the present invention, unlike conventionaltechniques there is no need for contact part extension for the purposeof improving casing rigidity. This makes it possible to sufficientlysecure the non-contact parts (30, 31, 32). Accordingly, the movement offluid in the inside of the casing (6) is not prevented, and there is nodrop in the efficiency of fluid machinery.

Furthermore, in accordance with the present invention, there is no needto increase the thickness of a casing for the purpose of improving itsrigidity, thereby preventing the increase in compressor weight itself.Additionally, some change in design allows conventionally-usedconstituent elements to be appropriated for the casing (6) et cetera,thereby making it possible to hold down the increase in the costs ofproduction of the compressor itself.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an entire cross-sectional view of an enclosed type compressoraccording to an embodiment of the present invention;

FIG. 2 is a schematic top plan view of a bearing housing of a scrolltype compression mechanism according to an embodiment of the presentinvention;

FIG. 3 is a schematic top plan view of a stator of an electric motoraccording to an embodiment of the present invention; and

FIG. 4 is a schematic top plan view of a lower main bearing according toan embodiment of the present invention.

BEST MODE FOR CARRYING OUT INVENTION

Hereinafter, embodiments of the present invention will be described indetail with reference to the drawings.

Referring to FIG. 1, there is shown an enclosed type compressor (1)according to an embodiment of the present invention. The enclosed typecompressor (1) is a compressor which comprises a compression mechanism(2) which is a scroll type compression mechanism, an electric motor (3),a drive shaft (4), and a lower main bearing (5) as a bearing (5) whichsupports one end of the drive shaft (4). The enclosed type compressor(1) is disposed in a refrigerant circuit of an air conditioner or thelike and is so constructed as to compress fluid refrigerant.

The electric motor (3) imparts, through the drive shaft (4), motiveenergy to the scroll type compression mechanism (2). The constituentcomponents, namely, the scroll type compression mechanism (2), theelectric motor (3), and the lower main bearing (5), are housedhermetically within a casing (6) substantially shaped like a cylinder.In the present embodiment, the enclosed type compressor (1) is avertical type compressor. The scroll type compression mechanism (2) isdisposed in an upper part of the inside of the casing (6). The lowermain bearing (5) is disposed in a lower part of the inside of the casing(6). Disposed between the scroll type compression mechanism (2) and thelower main bearing (5) is the electric motor (3). A suction port (7)through which refrigerant is drawn is defined in a body section of thecasing (6), i.e., a section between the scroll type compressionmechanism (2) and the electric motor (3). On the other hand, a dischargeport (8) through which refrigerant compressed is emitted is defined in ahead section of the casing (6), i.e., a section above the scroll typecompression mechanism (2).

In the present embodiment, the scroll type compression mechanism (2)includes a fixed scroll (10), a movable scroll (11), and a bearinghousing (12). As can be seen from FIG. 2, the bearing housing (12) isprovided with a circular seat portion (14) and leg portions (13)extending radially from the seat portion (14).

The fixed scroll (10) and the movable scroll (11) are each provided witha spiral lap. The fixed scroll (10) and the movable scroll (11) arearranged such that their laps engage with each other. Such engagement ofthe laps of the scrolls defines a compression chamber (40). A dischargeopening (41) through which refrigerant compressed in the compressionchamber (40) is discharged is defined centrally in the fixed scroll(10).

The fixed scroll (10) is attached firmly to the bearing housing (12).The movable scroll (11) is placed, through an Aldham's ring, in the seatportion (14) of the bearing housing (12). An eccentric portion (9)formed at a shaft end of the drive shaft (4) catches the back face ofthe movable scroll (11).

The scroll type compression mechanism (2) is fixed to the casing (6) bywelding, with ends of the leg portions (13) of the bearing housing (12)in contact with an inner wall surface of the casing (6). The bearinghousing (12) may be secured tightly to the casing (6) by other thanwelding, such as shrink fitting and press fitting.

The scroll type compression mechanism (2) is attached firmly to thecasing (6) in the way described above. As a result, in a first planeorthogonal to the longitudinal direction of the casing (6) five firstcontact parts (20) at which the ends of the leg portions (13) formed inthe bearing housing (12) of the scroll type compression mechanism (2)make contact with the casing (6) and five first non-contact parts (30)at which the bearing housing (12) does not make contact with the casing(6) are formed on the casing (6). These five first non-contact parts(30) of the scroll type compression mechanism (2) according to thepresent embodiment have the same length (Lc).

Referring again to FIG. 1, in the present embodiment the electric motor(3) is made up of a stator (16) and a rotor (17). As shown in FIG. 3,the stator (16), shaped like an octagonal prism, is formed bysuperimposing a large number of substantially octagon-shaped flatplates. Groove-like notch portions (15) and projecting portions (18) areformed in alternating manner, in every other side face of the octagonalprism. Defined centrally in the stator (16) is a cylindrical space intowhich the rotor (17) is inserted.

The electric motor (3) is attached firmly to the casing (6), with theprojecting portions (18) of the stator (16) in contact with the innerwall surface of the casing (6). The stator (16) may be secured tightlyto the casing (6) by known techniques such as press fitting and shrinkfitting.

The electric motor (3) is attached firmly to the casing (6) in the waydescribed above. As a result, in a second plane orthogonal to thelongitudinal direction of the casing (6), eight second contact parts(21) at which each projecting portion (18) of the stator (16) makescontact with the casing (6) and eight second non-contact parts (31) atwhich the stator (16) does not make contact with the casing (6) becauseof the notch portions (15) of the stator (16) are formed on the casing(6). In the electric motor (3) of the present embodiment, of the eightsecond non-contact parts (31) four second non-contact parts (31) have aperipheral length of Lm1 and the remaining four second non-contact parts(31) have a peripheral length of Lm2. Further, the second non-contactparts (31) of the length Lm1 and the second non-contact parts (31) ofthe length Lm2 are alternately arranged.

As shown in FIG. 4, the bearing (5) according to the present embodimenthas a bearing portion (19) as the lower main bearing (5) and three legportions (13) extending radially from the bearing portion (19). A lowerend of the drive shaft (4) is inserted rotatably into the bearingportion (19) and is supported there.

The lower main bearing (5) is housed in the inside of the casing (6),with the lower end of the drive shaft (4) inserted into the bearingportion (19) and is attached firmly to the casing (6) by welding, withthe ends of the leg portions (13) in contact with the inner wall surfaceof the casing (6). The lower main bearing (5) may be secured tightly tothe casing (6) by other than welding, such as shrink fitting and pressfitting.

The lower main bearing (5) is attached firmly to the casing (6) in theway described above. As a result, in a third plane orthogonal to thelongitudinal direction of the casing (6), three third contact parts (22)at which each leg portion (13) of the lower main bearing (5) makescontact with the casing (6) and three third non-contact parts (32) atwhich the lower main bearing (5) does not make contact with the casing(6) are formed on the casing (6). These three third non-contact parts(32) with respect to the lower main bearing (5) according to the presentembodiment have the same length (Lb).

In the enclosed type compressor (1) according to the present embodiment,the numbers of the non-contact parts (30, 31, 32) are as follows. Thenumber of the first non-contact parts (30) in non-contact with thescroll type compression mechanism (2) is five. The number of the secondnon-contact parts (31) in non-contact with the electric motor (3) iseight. The number of the third non-contact parts (32) in non-contactwith the lower main bearing (5) is three. The numbers of the non-contactparts (30, 31, 32) are neither a devisor nor a multiple.

It should be noted that the numbers of the non-contact parts (30, 31,32) are not limited to the foregoing values. Other combinations of thenumbers of the non-contact parts (30, 31, 32) may be used. For example,there is such a combination that the numbers of the non-contact parts(30, 31, 32) are five, four, and three, respectively. There is anothercombination in which the numbers of the non-contact parts (30, 31, 32)are five, seven, and three, respectively.

Operating Action

The operating action of the enclosed type compressor (1) will bedescribed below.

When the electric motor (3) is driven, the rotor (17) starts rotatingwith respect to the stator (16) attached firmly to the casing (6).During that period, vibrations produced in the electric motor (3)propagate to the casing (6) by way of the projecting portions (18) ofthe stator (16).

When the drive shaft (4) starts rotating, the eccentric portion (9)formed at the shaft end of the drive shaft (4) rotates around the driveshaft (4). Rotational movement of the eccentric portion (9) causes themovable scroll (11) engaging the eccentric portion (9) to move aroundthe fixed scroll (10). As a result of this, refrigerant from the suctionport (7) is drawn into the compression chamber (40) of the scroll typecompression mechanism (2). The refrigerant thus drawn is compressed whenthe volume of the compression chamber (40) is contracted toward thecenter with the revolution of the movable scroll (11).

With the volume variation of the compression chamber (40), therefrigerant is compressed to a high pressure and is discharged into thecasing from the discharge opening (41) formed centrally in the fixedscroll (10). The discharged refrigerant is delivered to a refrigerantcircuit through the discharge port (8) defined at a specific location ofthe casing (6). Then, the refrigerant is subjected to a condensationprocess step, to an expansion process step, and to an evaporationprocess step and thereafter is again drawn into the suction port (7) forcompression. During that period, vibrations caused by friction betweenthe fixed scroll (10) and the movable scroll (11) and by dischargepulsation of the high-pressure refrigerant propagate to the casing (6)by way of the bearing housing (12).

When the drive shaft (4) starts rotating, the bearing portion (19) ofthe lower main bearing (5) slides against the lower end of the driveshaft (4). At that time, vibrations caused by friction between thesliding surfaces and by run-out of the drive shaft (4) propagate to thecasing (6) by way of the leg portions (13).

Effects of Embodiment

The vibrations propagated to the casing (6) from each of the constituentcomponents will cause noise at the non-contact parts (30, 31, 32).

Since the enclosed type compressor (1) according to the presentembodiment is constructed in the way as described above, the peripherallength Lc of the first non-contact part (30) for the compressionmechanism (2), the peripheral length Lm1 of the second non-contact part(31) for the electric motor (3), the peripheral length Lm2 of the secondnon-contact part (31) for the electric motor (3), and the peripherallength Lb of the third non-contact part (32) for the lower main bearing(5) differ from one another. As a result, noise occurring at the firstnon-contact part (30), noise occurring at the second non-contact part(31), and noise occurring at the third non-contact part (32) differ infrequency from one another. This prevents only sound of a particularfrequency of the noises occurring at the non-contact parts (30, 31, 32)from resonating and from being amplified. Further, sounds of differentfrequencies are averaged or cancelled, thereby reducing the noise of theenclosed type compressor (1) as a whole.

Furthermore, in the enclosed type compressor (1) according to thepresent embodiment sufficient spaces are secured between each legportion (13) of the bearing housing (12), between the notch portions(15) formed in the side face of the stator (16), and between each legportion (13) of the lower main bearing (5). As a result of sucharrangement, movement of the refrigerant in the inside of the casing (6)will not be prevented and the drop in compression efficiency will nottake place.

Further, it is possible to prevent not only the increase in weight ofthe enclosed type compressor (1) but also the increase in costs of theenclosed type compressor (1).

Modifications

As other embodiments of the enclosed type compressors (1) of the secondand third inventions, there is an enclosed type compressor in which thediameter of the casing (6) is varied. The body section of the casing (6)of the first embodiment is shaped like a cylinder having the samediameter from top to bottom. In stead of employing such a casing (6),the diameter of the casing (6) is varied at a location at which thescroll type compression mechanism (2) is attached firmly to the casing(6), at a location at which the electric motor (3) is attached firmly tothe casing (6), and at a location at which the lower main bearing (5) isattached firmly to the casing (6).

As a result of such arrangement, the first non-contact part (30), thesecond non-contact part (31), and the third non-contact part (32), whichdiffer in their peripheral length from one another, are formed in afirst, a second, and a third plane, respectively.

In other words, a first contact part (20) which makes contact with thescroll type compression mechanism (2) and a first non-contact part (30)which does not make contact with the scroll type compression mechanism(2) are formed in the first plane orthogonal to the longitudinaldirection of the casing (6). A second contact part (21) which makescontact with the electric motor (3) and a second non-contact part (31)which does not make contact with the electric motor (3) are formed inthe second plane orthogonal to the longitudinal direction of the casing(6). A third contact part (22) which makes contact with the bearing (5)and a third non-contact part (32) which does not make contact with thebearing (5) are formed in the third plane orthogonal to the longitudinaldirection of the casing (6).

In this case, even when the number of the first non-contact parts (30),the number of the second non-contact parts (31), and the number of thethird non-contact part (32) are the same, the diameter of the casing (6)is varied depending on the locations of these non-contact parts. As aresult, the first to third non-contact parts (30, 31, 32) have differentperipheral lengths, whereby the same effects that the aforesaidembodiment provides can be obtained.

Furthermore, as other embodiments of the first and second inventions,there is an embodiment which does not include the lower main bearing (5)in the inside of the casing (6).

Further, as another embodiment of the enclosed type compressor (1)according to the second embodiment, a rotary type compression mechanismmay be employed in place of the scroll type compression mechanism (2).

The enclosed type compressor (1) of the present invention is acompressor disposed in a refrigerant circuit. However, the enclosed typecompressor (1) may of course be a compressor for compressing varioustypes of fluids.

INDUSTRIAL APPLICABILITY

As has been described, the present invention provides an enclosed typecompressor which proves useful when employed in airconditioners andrefrigerating machines. The enclosed type compressor of the presentinvention is suitably used particularly in cases where a compressionmechanism and an electric motor are attached firmly to a casing.

1. An enclosed type compressor comprising a scroll type compressionmechanism (2), an electric motor (3) for driving said compressionmechanism (2), and a cylindrical casing (6) for housing said compressionmechanism (2) and said electric motor (3), in which said compressionmechanism (2) and said electric motor (3) are attached firmly to saidcasing (6), with said compression mechanism (2) and said electric motor(3) in contact with an inside face of said casing (6), wherein: in afirst plane orthogonal to the longitudinal direction of said casing (6)said casing (6) is in contact with said compression mechanism (2) in afirst contact part (20) and is out of contact with said compressionmechanism (2) in a first non-contact part (30), in a second planeorthogonal to the longitudinal direction of said casing (6) said casing(6) is in contact with said electric motor (3) in a second contact part(21) and is out of contact with said electric motor (3) in a secondnon-contact part (31), and wherein said first non-contact part (30) andsaid second non-contact part (31) have different peripheral lengths. 2.An enclosed type compressor comprising a compression mechanism (2), anelectric motor (3) for driving said compression mechanism (2), and acasing (6) for housing said compression mechanism (2) and said electricmotor (3), in which said compression mechanism (2) and said electricmotor (3) are attached firmly to said casing (6), with said compressionmechanism (2) and said electric motor (3) in contact with an inside faceof said casing (6), wherein: in a first plane orthogonal to thelongitudinal direction of said casing (6) said casing (6) is in contactwith said compression mechanism (2) in a first contact part (20) and isout of contact with said compression mechanism (2) in a firstnon-contact part (30), in a second plane orthogonal to the longitudinaldirection of said casing (6) said casing (6) is in contact with saidelectric motor (3) in a second contact part (21) and is out of contactwith said electric motor (3) in a second non-contact part (31), andwherein said first non-contact part (30) and said second non-contactpart (31) have different peripheral lengths.
 3. An enclosed typecompressor comprising a scroll type compression mechanism (2), anelectric motor (3) for driving said compression mechanism (2), a bearing(5) for supporting one end of a drive shaft (4) connecting saidcompression mechanism (2) and said electric motor (3), and a casing (6)for housing said compression mechanism (2), said electric motor (3), andsaid bearing (5), in which said compression mechanism (2), said electricmotor (3), and said bearing (5) are attached firmly to said casing (6),with said compression mechanism (2), said electric motor (3), and saidbearing (5) in contact with an inside face of said casing (6), wherein:in a first plane orthogonal to the longitudinal direction of said casing(6) said casing (6) is in contact with said compression mechanism (2) ina first contact part (20) and is out of contact with said compressionmechanism (2) in a first non-contact part (30). in a second planeorthogonal to the longitudinal direction of said casing (6) said casing(6) is in contact with said electric motor (3) in a second contact part(21) and is out of contact with said electric motor (3) in a secondnon-contact part (31), in a third plane orthogonal to the longitudinaldirection of said casing (6) said casing (6) is in contact with saidbearing (5) in a third contact part (22) and is out of contact with saidbearing (5) in a third non-contact part (32), and wherein said firstnon-contact part (30), said second non-contact part (31), and said thirdnon-contact part (32) have different peripheral lengths, respectively.4. The enclosed type compressor of any one of claims 1-3, wherein aplurality of said first contact parts (20) and a plurality of said firstnon-contact parts (30) with respect to said compression mechanism (2)are formed in said casing (6), and wherein at least one of saidplurality of said first non-contact parts (30) with respect to saidcompression mechanism (2) has a peripheral length different from that ofthe other first non-contact parts (30).
 5. The enclosed type compressorof any one of claims 1-3, wherein a plurality of said second contactparts (21) and a plurality of said second non-contact part (31) withrespect to said electric motor (3) are formed in said casing (6), andwherein at least one of said plurality of said second non-contact parts(31) with respect to said electric motor (3) has a peripheral lengthdifferent from that of the other second non-contact parts (31).
 6. Theenclosed type compressor of claim 3, wherein a plurality of said thirdcontact parts (22) and a plurality of said third non-contact parts (32)with respect to said bearing (5) are formed in said casing (6), andwherein at least one of said plurality of said third non-contact parts(32) with respect to said bearing (5) has a peripheral length differentfrom that of the other third non-contact parts (32).
 7. The enclosedtype compressor of either claim 1 or claim 2, wherein the number of saidfirst contact parts (20) differs from the number of said second contactparts (21).
 8. The enclosed type compressor of claim 3, wherein thenumber of said first contact parts (20), the number of said secondcontact parts (21), and the number of said third contact parts (22)differ from one another.
 9. The enclosed type compressor of either claim1 or claim 2, wherein the number of said first non-contact parts (30) isneither a multiple nor a divisor of the number of said secondnon-contact parts (31).
 10. The enclosed type compressor of claim 3,wherein: the number of said first non-contact parts (30) is neither amultiple nor a divisor of the number of said second non-contact parts(31), the number of said second non-contact parts (31) is neither amultiple nor a divisor of the number of said third non-contact parts(32), and the number of said third non-contact parts (32) is neither amultiple nor a divisor of the number of said first non-contact parts(30).